<!DOCTYPE html>
<link rel="author" title="Mats Palmgren" href="mailto:mats@mozilla.com">
<meta name="flags" content="paged">
<html>
<style>
@page {
  size: 5in 3in;
  margin: 0.5in;
}

html,body {
  color:black; background-color:white; font:20px/1 monospace; padding:0; margin:0;
  writing-mode: vertical-lr;
}
html { margin-block-start: 80vw; }
* { box-sizing: border-box; }

.b {
  inline-size: 50vh;
  border: 5px solid black;
  border-block-start-color: blue;
  border-inline-start-color: lime;
  margin-inline-start: 20px;
}
.b1 {
  block-size: 20vw;
  border-block-end-style: none;
}

.b2 {
  block-size: 100vw;
  border-block-start-style: none;
  border-block-end-style: none;
}

.b3 {
  block-size: 10vw;
  border-block-start-style: none;
}

.b > div {
  inline-size: 50vh;
  block-size: 100vw;
  border: 5px solid grey;
  margin-inline-start: 20px;
}
.b1 > div {
  border-block-end-style: none;
  margin-block-start: -5px;
}
.b2 > div {
  border-block-start-style: none;
  border-block-end-style: none;
}
.b3 > div {
  block-size: 30vw;
  border-block-start-style: none;
}

.after {
  inline-size: 60vh;
  block-size: 30vw;
  margin-block-start: 5vw;
  border: 5px solid blue;
}
</style>
<body>
  <div class="b b1"><div></div></div>
  <div class="b b2"><div></div></div>
  <div class="b b3"><div></div></div>
  <div class="after"></div>
</body>
</html>
